Magnetron anode



Jan. 29, 1952 R. B. NELSON MAGNETRON ANODE Filed July 26, 1950 Inventor:Richard B. Ne lson,

by w 4 W His Attorney- Patented Jan. 29, 1952 PATENT OF P .I'CE

MAGNETRON ODE Richard B. Nelson, Schenectady,

EN. .Y., .ass'ignor to General Electric Company, :a vcorp-oration =01.New York Application July 26, 195(1, Ser'ialNmL175,979

.1 Claim.

"quency electromagneticart, as oscillators for in- :stance,usuallycomprises a group ofradially extending anodesegments forming attheir center ,;:a generally cylindrical chamber adapted to ac-:commodate a rotating space-charge. Between theanodesegments is-fQrmed aseries of'resonant cavities communicating with the space-charge Ichamber. The anodes and resonant cavities are in general .made .from asolid block of material. -As is well .known to those skilled in the art,the

normally loose .coupling between the individual resonant cavities.-frequently causes the mag- ;netron apparatus to function at undesired.frequencies and in undesired modes.

Heretofore, .to overcome this objection, it has been the practice tostrap alternate anodes.

.Strapping was accomplished by connecting to- ,gether alternate anodesat eachend of the .anode block. .Thisarrangement has not been completelysatisfactory, especially with anode blocks of long axial length.

:What I propose is to strap alternate anode segments along the axiallength of the anode structure .as .wellas at the ends thereof. 'In thisway a more stable operation in the magnetron apparatus is obtained, andfurthermore, anode structures of longer axial length can be used withall the resultant advantages.

Therefore, it is an object of the presentiuvention to provide animproved anode structure which .is simple to construct and which hasimproved performance qualities.

fItis a further object 'of "the'present invention toprovide an anodestructure with strapping of alternate anode segments along the axiallength of the anode structure as well as at the ends of the anodestructure.

In the exemplary embodiment shown in the drawing the foregoing objectsare achieved by forming the anode section from a group of dissimilarlaminations. Each lamination is so constructed such that when the groupof laminations is assembled or stacked together they form an anodestructure in which short-circuiting straps are formed along the lengthof anode structure as well as near the ends of the anode structure.

The features of the invention desired to be protected are pointed out inthe appended claim. The invention itself together with its furtherobjects and advantages may be understood by reference to the followingdescription and to the appended drawing in which Fig. 1 shows anexpanded view of a unit group of laminations; Fig. 2

shows *a p'lan view in partial :section of the laminations of Fig.1stacked together to rorm a unit group; Fig. 3 shows aside viewinsectionof the lamination of Fig. 1 stacked'together to form a unitgroup.

Referring nowto Fig. l there is shown a-group of =laminations l, "2, 3,3, 5, 6 and of the kind utilized to form the improved anode structureor" the invention. "From an examination of this figure itisrea'dilyapparent that generally speak- *ing eacher the laminations areconstructed in .a. manner so that when the laminaticns of the group arestacked together they form a unitsecton of an anode structure in :whichalternate ..node segments are strapped together. The laminations aremade zfrom the usual conductive material employed in anode structures,for example, copper. Around the periphery of each of the laminations aredistributed a series of aliening holes 8. These holes are for thepurposeof receiving pins -to mold the laminations in alignment-whilethey are soldered together. .An alloy of'silver and copper, or :asimilar solder, is suitable for this purpose. If desired, in order '170decrease #the losses :in the anode structure, the anode structure may:be plated with silver. .11; should be :understood that unit. groups oflaminations may be stacked together ltO iorm an anode structureofrelatively long axial length inxwhich there is strapping distributedalong the axial length, one pair of .straps being incorporated .tin eachunit group. When an :anode structure 101 this construction isincorporated .into the mag- =netrondevice :an improved magnetron devicefree from the aforementioned defects is .obtained.

Referring now to a :detailed, description :of the laminations shown inFig. 1, .ilamination I comprises a series of radially extending anodesections 9 in insulated relationship at their inner ends and forming attheir inner ends a generally cylindrical space adapted to accommodate ardtating space-charge. The other ends of the anode sections areconductively connected by a ring I so that in eifect a series ofopenings II is formed between adjacent anode sections. These openings llcommunicate with the aforementioned space-charge space. The openings llcomprise the resonators of the magnetron when the individual laminationsare stacked together in operative relationship. Lamination 2 comprises athin plate similar to lamination l except that the alternate anodesections l2 are truncated in the manner shown to about half the lengthof the other anode section [3. Lamination 3 is similar to the secondlamination except 56 that the long anode sections I 4 are connected Vrespectively,

. .ing straps.

together by means of shorting bars I5. In addition, at the end of eachlong anode section is located a protuberance l6 about the width of thetip of the long anode section extending perpendicular to the plane ofthe laminations for three thicknesses of an individual lamination. Thetruncated sections 11 of lamination 3 do not make contact with theshort-circuiting straps I5 01' with the long anode section M at theirtruncated ends. Lamination 4 comprises a structure similar to thestructure of the lamination 2 except that all of the anode sections [8are truncated. Lamination 5 comprises a structure identical with thestructure of the lamination 3. However, when lamination 5 is assembledwith the other laminations the protuberances IQ of this lamination facein opposite direction from the protuberdially extending anode sectionsat one end formances on lamination 3 and the protuberances of lamination5 are aligned so that the long anode sections on the lamination 5 arestacked over the short lamination sections on lamination 3. -With thisstacking arrangement the protuberances of the fifth and the third anodesections are located ,side by side and separated from each other whenall of the laminations are stacked together as shown in Fig. 2. Inlamination 5 as well as in lamination 3, the portion of theshort-circuiting strap between long anode sections is recessed so ,as toaccommodate the protuberance from the other anode section. It isessential that these protuberances avoid conductive contact with theshorting straps. -.the second anode lamination except that in theLamination 6 is identical with assembly of the group of laminationslamination .6.is stacked so that its truncated anode sections arelocated over the long anode sections of the I lamination 2.

.Referring now to Figs. 2 and 3, there are shown,

plan and side views of the laminations of Fig. 1 assembled to form amagnetron anode structure. Fig. 3 is a sectional view taken alongsection 33 of Fig. 2. On the assembled anode structure theaforementioned short-circuiting straps connect alternate composite anodesections. Elements l5 in Fig. 3 are short-circuit- .While a unit groupof an anode structure has been described, it is readily appreciated thatby stacking unit groups of laminations together an anode structure oflong axially length is obtained with all'the resultant advantages of a 1long anode structure. With the strapping along the'axial length of theanode structure, the magnetron apparatus in which it is incorporated hasconsiderably less tendency to operate at undesired frequencies.

While I have shown and described particular embodiments .of myinvention, it will be obvious ing a portion of a generally cylindricalchamber and at the other end terminated in a ring to form an opening insaid lamination between said anode sections and communicating with saidchamber; a second lamination similar to said first lamination and havingalternate anode sections truncated; a third lamination similar to saidsecond except that the long anode sections are connected together by ashort-circuiting strap, said long anode section having a protuberance onthe end thereof perpendicular to the plane of said lamination, saidshort-circuiting strap being recessed from the extreme end of the longanode section, said truncated anode sections making no direct conductiveconnection with a long anode section at the end adjacent the chamber,the length of said protuberances being about the thickness of threelaminations; a fourth lamination having all anode sections truncated; atfifth anode lamination similar to said third lamination except with saidprotuberances facing in the opposite direction and with the alternateset of anode sections truncated; a

" sixth anode lamination identical to said second circuits formedbetween adjacent anode segments within said anode structurecommunicating with said chambers and short-circuiting strapsconductively connecting alternate anodes within the ,body of said anodestructure.

RICHARD B. NELSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,432,827 Spencer Dec. 16, 194"!2,443,445 Donal, Jr., et al. June 15, 1948

